Phosphorus loss of calcium: the imbalance of calcium and phosphorus ratio is the chief culprit leading to calcium deficiency. Under normal circumstances, the ratio of calcium and phosphorus in human body is 2∶ 1. However, in real life, people eat too many phosphorus-containing foods, such as carbonated drinks, cola, coffee, hamburgers, pizza, wheat germ, animal liver, French fries, etc., which makes the calcium-phosphorus ratio as high as1:10 ~ 20.
Calcium supplementation does not supplement magnesium, and you will regret eating it: people only pay attention to vitamin D when supplementing calcium, but often don't know about magnesium supplementation. Like twin brothers, calcium and magnesium always appear in pairs, and the ratio of calcium and magnesium is 2∶ 1, which is most beneficial to the absorption and utilization of calcium. Therefore, when supplementing calcium, remember not to forget to supplement magnesium. Foods rich in magnesium include nuts (such as almonds, cashews and peanuts), soybeans, melon seeds (sunflower seeds and pumpkin seeds), cereals (especially rye, millet and barley) and seafood (tuna, mackerel, shrimp and lobster).
Big fish and big meat "eat" calcium: a high-protein diet is the cause of osteoporosis. Someone has done such an experiment: A: Taking 80 grams of protein every day will lead to 37 mg of calcium loss; B: Taking 240 grams of protein every day and supplementing 1400 mg of calcium will lead to the loss of 137 mg of calcium. Extra calcium supplementation can't prevent calcium loss caused by high protein. Excessive intake of big fish and meat without paying attention to acid-base balance will lead to a large loss of calcium. So, how does diet promote the absorption of calcium? Vitamin C promotes the absorption of calcium: If foods with high calcium content are taken together with vitamin C and pickle juice, or made into navel oranges, grapefruit, oranges, citrus and lemons, the bioavailability will be enhanced by 65,438+02%. Obviously, it is the participation of a large amount of vitamin C in these fruits that makes calcium better absorbed by the small intestine.
Balance between meat and vegetables improves the utilization rate of calcium: for example, stewed fish with tofu contains vitamin D, and tofu is rich in calcium. Vitamin D can promote the absorption of calcium and greatly improve the utilization rate of calcium in tofu. In addition, the staple food pays attention to the collocation of cereals and beans, which can not only complement amino acids to the best, but also promote the absorption of calcium.
1. Do you need calcium?
Many experts in the world believe that calcium deficiency is a serious disease that threatens human beings at present, which makes hundreds of millions of people around the world suffer great mental and physical torture and directly affects the improvement of human quality. Experts call on all sectors of society to attach great importance to it!
Of the calcium obtained by the fetus from the mother, 99% is used for bone formation, and only 1% is free in the blood in the form of ionized calcium, which is called "serum calcium". However, the data show that after birth, everyone is in a situation of calcium deficiency to varying degrees. People of any age are short of calcium, especially children and the elderly. Scientists found that from the age of 20, the total weight of bones decreased at the rate of 1% per year, and after the age of 50, the total weight of bones decreased by 30%-a scientific and amazing conclusion.
Because of "calcium hunger", the so-called "calcium movement" in the body is caused. In other words, the calcium in the bones is constantly escaping into the blood to maintain the normal level of serum calcium. The ratio of bone calcium to blood calcium must be kept in balance for a long time, otherwise there will be abnormal imbalance of calcium metabolism, such as "calcium movement" A person's calcium deficiency for a few days or a month or two will not affect serum calcium for the time being, but if this continues, calcium deficiency diseases will occur: children show sparse hair, anorexia, restlessness, night terrors, rickets, etc. Adolescent skeletal dysplasia, visual impairment, etc. ; Pain in pregnant women's waist and legs affects fetal development and even causes deformity; Osteoporosis, degenerative hyperosteogeny, lithiasis, hypertension, diabetes, dementia, etc.
Obviously, calcium plays an important role in the process of life.
Why do we eat calcium-containing foods every day, such as beans, dairy products, aquatic products, shells, bones and so on. And our bodies are still short of calcium? It turns out that the calcium contained in food is mostly dissolved calcium salt, which is not easy to be absorbed. Moreover, when eaten with cereals and dishes, phytic acid contained in cereals or fatty acids contained in meat will turn calcium into insoluble calcium salt, which cannot be absorbed. According to modern nutrition standards, the biological dose of calcium (ionized calcium for short) should not be less than 800 mg for adults and 1000 mg for children in China. Unfortunately, for a long time, the medical community mistakenly regarded calcium salt as pure calcium (that is, ionized calcium), so that many medicinal calcium in the past could not really supplement calcium. Fortunately, this fallacy has been discovered and corrected in recent years. A molecular calcium, a ionized calcium, only a word difference, triggered a worldwide human "calcium revolution"!
Calcium deficiency requires calcium supplementation, and everyone should raise their awareness of calcium supplementation. The question is, what kind of calcium should be supplemented and how should it be supplemented? Although the medical community has long recognized that calcium supplementation is a difficult problem, the ideal calcium preparation should meet three conditions, namely, ① it contains both high quantity and high quality pure calcium; ② It can be fully dissolved; ③ It is easy to be absorbed and utilized after taking. At present, many safe and efficient new calcium nutrition fortifiers have been developed, which are more and more in line with scientific requirements.
In daily food, the best sources of calcium are milk and dairy products, which are not only rich in content, but also have high absorption rate. It was found that the content of calcium in shrimp shell was very high, reaching 2000 mg/ 100 g, and it had good solubility. It is an ideal calcium supplement for biological protein calcium crystals, and eating shrimp shell meat is unscientific! Commonly used foods rich in calcium are beans (soybeans, mung beans, black beans and their products), walnuts, sesame seeds, seaweed, kelp and so on.
However, please remember: it is best to take calcium on an empty stomach one hour before meals.
2. Shortcut of calcium supplement-eat less salt
I remember there is a saying in the ancient art of war: winning by war is not the best policy; Winning without fighting is the best policy. Applying this sentence to the problem of calcium supplementation is: if you don't supplement calcium, you can achieve the effect of calcium supplementation, and fear is the most ideal method of calcium supplementation. So, is there such a way to supplement calcium without supplementing calcium? The answer is yes, this is the shortcut to calcium supplement-eat less salt.
The method of eating less salt to supplement calcium was first put forward by British scientists. In their research, they found that the intake of salt in the diet is the main determinant of calcium excretion. That is, the more salt intake, the more calcium is excreted with urine, and the more salt intake, the worse calcium absorption. So they come to the conclusion that reducing salt intake properly is as good for bones as increasing 900 mg of calcium! In other words, eating less salt is equal to supplementing calcium, and eating less salt actually plays the role of "not supplementing calcium".
According to the statement that China residents are generally short of calcium, normal people should consume 800- 1200mg of calcium every day, and the most conservative statement is that they should consume 300-500mg of calcium every day. But in any case, eating less salt is equivalent to supplementing 900 mg of calcium every day, which can meet the basic needs of the human body for calcium. Even if there are still some shortcomings, eating less salt can increase the absorption of calcium.
Eating less salt and supplementing calcium is suitable for all people. For example, girls who grow fast eat more salt, and the excretion of calcium increases and the absorption decreases, which will lead to decalcification of bones and bone dysplasia. Another example is postmenopausal women, and the incidence of osteoporosis is already high. If you eat more salt, not only the amount of urine calcium increases, but also the loss of bone calcium increases, which will accelerate the occurrence of osteoporosis. In one study, the daily salt intake of postmenopausal women was reduced from 10.6 g to 4.4 g, and the calcium excretion and plasma calcium concentration were greatly reduced. Furthermore, if hypertensive patients continue to eat a high-salt diet, their urinary calcium excretion is much higher than that of people with normal blood pressure, and the potential danger of bone decalcification is also greater than that of people with normal blood pressure. On the contrary, eating less salt can reduce their urinary calcium and increase their bone density.
According to the standards recommended by WHO, it is advisable to take 5 grams of salt every day, not more than 6 grams. We know that people excrete 3-5 grams of salt in 24 hours, so adding 5 grams of salt to food every day is just the amount lost and replenished, which can meet normal needs. It is not easy to limit the salt intake to less than 5 grams a day. This needs to change our eating habits. Because in China, especially in the north, people generally eat more salt, which is more than12g per day, and in some places it is as high as 20-30g. It is also quite difficult to change people's traditional habit of eating salty food at once. But when people know that eating less salt can supplement calcium, or they can supplement calcium without spending money, we can gradually reduce the amount of salt in our daily life, which I think is still possible.
In Beijing, Shanghai and other places, the salt containing potassium, magnesium and low sodium has been listed, and the sodium content of this salt is only 65% of that of ordinary salt. If you eat this salt regularly, it will reduce the salt content of 1/3. Qiu Shi is a traditional Chinese medicine, and its main component is potassium chloride. Buy it, grind it, and mix it with salt in half, which can also reduce the salt 1/2.
Of course, reducing salt can also help you prevent and treat high blood pressure, reduce the risk of cardiovascular and cerebrovascular diseases, and at the same time let you lose weight, so as to achieve the purpose of losing weight and bodybuilding.
3. Why do you still lack calcium after years of calcium supplementation?
In the treatment of calcium supplementation, we often encounter a common problem, that is, some people still lack calcium after taking calcium for several years, and doctors still say osteoporosis when checking bone density. Why is this? We should understand this problem from the following aspects.
Most scholars recommend that the calcium intake for preventing osteoporosis should reach 1000- 1500mg per day. At present, most calcium preparations produced in China indicate the dosage according to the amount of calcium salt, but the amount of calcium salt is quite different from the content of calcium. For example, calcium lactate only contains 1 gram every 8 grams. The dosage of calcium supplementation must be supplemented according to the calcium content. For example, the calcium content of the commonly used Gaitianli and Holly calcium tablets is 25mg, which means that if the dietary calcium supplement reaches 600mg per day, at least 24 tablets (600mg) of Gaitianli and Holly calcium tablets should be taken every day to meet the needs of the elderly and osteoporosis patients. The principle of supplementing other calcium agents is the same, that is, according to the calcium content indicated by the manufacturer, instead of the amount of calcium salt, it is generally 600 mg per day. The dose is too small, of course, you can't get the effect of calcium supplementation.
Under normal conditions, the ratio of phosphorus to calcium in bones is 0.6, that is, there is 2 milliequivalents/liter of phosphorus for every 3 milliequivalents/liter of calcium. If the ratio of calcium to phosphorus is not appropriate, it will affect the absorption and utilization of calcium. In particular, the lack of phosphorus will lead to bone loss. Due to the decrease in intake and fear of phosphorus-rich foods such as fish, liver, meat and eggs, the elderly are not eating enough. Although they supplemented enough calcium, due to insufficient phosphorus, calcium deposition did not increase significantly. The reason why fresh milk is beneficial to osteoporosis is that the proportion of calcium and phosphorus in milk is appropriate, which can supplement calcium and phosphorus.
Improper food composition If you take too much food containing phytic acid, oxalic acid, tannic acid (such as spinach) and fatty acids (mainly lard and fat) while supplementing calcium, it will combine with calcium and reduce its absorption. In addition, some high-quality protein (such as beef, fish, seafood, lean pork, etc. ) can release amino acids in the process of intestinal digestion, which can reduce the acidity of intestinal tract, form hard-to-absorb calcium salt with calcium, and also reduce the absorption of calcium. Therefore, while supplementing calcium, we should avoid the interaction and influence of food ingredients to reduce the loss of calcium.
There are many hormones that can promote intestinal calcium absorption, the most important one is active vitamin D3. The low level of active vitamin D3 in the elderly affects the absorption and utilization of calcium. At the same time, active vitamin D3 needs to be supplemented. Other hormones that promote intestinal calcium absorption include estrogen, androgen, growth hormone and calcitonin. After menopause, estrogen decreases and intestinal calcium absorption decreases. After estrogen supplementation, intestinal calcium absorption increased and bone mass increased. Estrogen supplementation should be started as soon as possible after menopause, at least until the age of 75. Other hormones can also be supplemented in an appropriate amount to increase the effect of calcium supplementation. Of course, hormone supplementation must be carried out under the guidance of an experienced doctor.
Too little outdoor exercise will lead to osteoporosis or accelerate the occurrence of osteoporosis. If you insist on outdoor sports and receive sunshine every day, you can even refuse to accept active vitamin D3. In our country, the bone content of southerners is higher than that of northerners, because the south receives more sunlight than the north.
4. Who should supplement calcium?
Calcium supplementation is considered by many people to be only needed by children and rickets patients. Actually, this view is not comprehensive. There are many patients in clinic who need calcium supplementation.
The typical symptoms of diabetic patients are "three more and one less", that is, drinking more, eating more, urinating more and losing weight. Due to osmotic diuresis, calcium excretion in the body increases, leading to diabetic osteopathy, bone thinning, osteoporosis and even pelvic deformity or pathological fracture.
Elderly osteoporosis patients over middle age, due to endocrine dysfunction, too little activity, insufficient calcium intake and other factors, bone metabolism is impaired, bone formation is reduced, calcium is lost too much, and osteoporosis, bone degeneration, low back pain, hunchback and even pathological fractures occur.
Some pregnant women have low back pain and calf cramps. Due to the growth and development of the fetus, the demand for calcium increases, which leads to calcium deficiency in pregnant women. In addition, low birth weight infants, premature infants, malnourished infants and children with chronic diarrhea should pay attention to calcium supplementation. Calcium deficiency in children will not only affect growth and development, but also lead to many diseases.
Scientific research in recent years has proved that long-term use of antiepileptic drugs in epileptic patients will lead to different degrees of bone mineral density reduction and abnormal bone metabolism. Once calcium deficiency often leads to seizures, it is difficult to control and needs long-term use.
People who drink a lot of alcohol for a long time or often drink tea and coffee should pay attention to calcium supplementation. Because of drinking, bone metabolism disorder, easy to cause osteoporosis. Drinking tea and coffee for a long time will increase the excretion of calcium due to diuresis, which will easily lead to calcium deficiency in the body.
Hypoparathyroidism "hypoparathyroidism" or hypoparathyroidism can lead to decreased intestinal calcium absorption, which in turn leads to decreased blood calcium. The patient has a series of symptoms, such as numbness, tingling, stiffness and spasm.
Calcium supplementation should pay attention to the following points: ① Try to take calcium from the diet and eat more foods rich in calcium. ② For patients with diabetic osteopathy, besides actively treating diabetes, calcitonin and calcium can be combined to promote the formation of osteoblasts. ③ Old people and children with calcium deficiency should pay attention to increasing outdoor activities and getting more sunshine. ④ Pay attention to the supplement of protein and vitamin D to promote the absorption of calcium, but the dosage of calcium supplement should not be too large to prevent urinary calculi.
5, dietary calcium supplementation should be regular.
Calcium supplementation is an important topic of health care. Many diseases such as numbness, cramp, obesity, edema, constipation, hypertension, arteriosclerosis and osteoporosis in the elderly are related to calcium deficiency. The daily calcium intake of the elderly should be above 1000 mg, while the daily calcium intake is only 300-500 mg. It is important to eat some high calcium nutrition, but it is more economical and practical to supplement calcium through daily diet.
Half a catty of milk contains 300 mg of calcium, and also contains a variety of amino acids, lactic acid, minerals and vitamins to promote the digestion and absorption of calcium. Therefore, milk should be the main source of calcium supplementation.
Soybean is a high protein food with high calcium content. 500 grams of soybean milk contains calcium 120 mg, and 150 grams of tofu contains calcium as high as 500 mg. Other bean products are also good calcium supplements.
Kelp and shrimp skin Kelp and shrimp skin are high calcium seafood. Eating 25 grams a day can supplement 300 mg of calcium, reduce blood lipid and prevent arteriosclerosis. Shrimp skin contains a high amount of calcium, 500 mg in 25 grams.
More than 80% of animal bones are calcium, but it is insoluble in water and difficult to absorb. You can mash it, add vinegar and cook it slowly, or add soybeans and ginger salt.
There are also many high-calcium varieties in vegetable sparse, and potherb mustard 100 g contains 230 mg of calcium; The contents of Chinese cabbage, rape, fennel, coriander and celery are also around 150 mg. These green leafy vegetables can supplement 400 milligrams of calcium by eating 250 grams a day.
Sesame Sesame is a good health care product for the elderly and a source of calcium supplement, which can be taken in moderation. Sesame sauce also contains high calcium, and sesame sauce can be added to porridge, noodle soup and cold salad to supplement calcium.
The absorption and utilization of calcium by human body is a complex problem. Even the most digestible milk has a calcium absorption rate of only 50%, and the absorption rate of other calcium-containing foods is even lower. Vitamin D can regulate the metabolism of calcium and phosphorus in the body and promote the absorption and utilization of calcium. The sources of vitamin D are: first, the human body is exposed to outdoor sunlight and ultraviolet rays and synthesized in the body; The second is food. Except cod liver oil, the content of other foods is extremely low. Only mushrooms are rich in vitamin D, and each gram contains vitamin D40 international units. But it must be exposed in the outdoor sun, but the effect of exposure will decrease day by day, so it should be used repeatedly after one month. Take 3-5g daily, chop it up, decoct it in water or take it with water, or add it to porridge and vegetable soup. More jealous and mellow pasta also contributes to the absorption of calcium.
Our current dietary structure is low in calcium, so we must pay attention to adding some calcium-supplemented foods. Because calcium absorption is difficult, calcium supplementation is slow, and it takes months or even a year or two to improve symptoms. Only by carrying out the idea of "multiple varieties, frequent changes, more intake, and constant regularity" can we achieve the ideal calcium supplement and health care effect.
6. Patients with stones also need calcium supplementation.
Whether gallstones, stones in kidney calculi or stones in other parts of the human body, the main component is insoluble calcium salt. There used to be a theory that the cause of the disease was that the human body ingested too much calcium, which caused the deposition of calcium in the body. Under the guidance of this theory, it is suggested that patients with lithiasis should eat less food containing more calcium to prevent and treat stones. However, recent studies have found that lithiasis is not caused by excessive calcium intake, but the result of calcium metabolism disorder in the body.
Nutritional and epidemiological surveys in China show that calcium intake from diet, including patients with lithiasis, is still at the lower limit of the body's requirements or even lower than the decline. Most modern people eat too carefully, resulting in insufficient calcium intake, and the body is often in a state of calcium deficiency. The metabolic balance of calcium in the body is controlled by a system called calcium metabolic stability. This system includes parathyroid gland, parathyroid hormone, calcitonin, vitamin D and so on. According to the intake and excretion, adjust the balance of calcium in all parts of the body. Mainly the balance of calcium in plasma and bones. Calcium deficiency in human body is first manifested in plasma. Due to the low content of calcium in plasma, people have to use calcium stored in bones to maintain normal physiological functions. When the body is often in a calcium-deficient environment, the calcium balance system needs to maintain the normal concentration of calcium in plasma and bones, which often leads to metabolic disorder, which is also called "blood calcium homeostasis system disorder" in medicine. The result of this disorder is abnormal "calcium migration", that is, the abnormal phenomenon of decreased bone calcium and increased blood calcium and soft tissue calcium content.
Abnormal migration of calcium will cause some seemingly contradictory diseases, such as osteoporosis, hyperosteogeny, calculus, arteriosclerosis and so on. In addition, several of these diseases often coexist in one patient. Japanese endocrinologist Tuo Fujita pointed out: "This phenomenon of calcium migration from bones to soft tissues and blood is a typical feature of aging." Only calcium supplementation can cure the disease. By stimulating the self-stabilizing system of blood calcium to restore balance, the purpose of reducing blood calcium and soft tissue calcium content and increasing bone calcium can be achieved. Therefore, patients with stones and hyperosteogeny also need calcium supplementation.
Active ionized calcium, such as pearl calcium and giant calcium, is the first choice for calcium supplementation for patients with stones. At the same time, pay attention to drink plenty of water and avoid eating foods containing oxalic acid and phosphate, such as water chestnut, amaranth, spinach, water bamboo, dried bamboo shoots and so on. If you eat the above vegetables, you should also blanch them with boiling water to remove oxalic acid and phosphate. Appropriately limit the intake of high-phosphorus foods, such as dairy products and meat. In addition, pay attention to eat more foods containing magnesium and vitamin B6, such as seaweed, sunflower seeds, soybeans, almonds and so on. The latter are fermented grains, brown rice, royal jelly, soybeans, black beans and fermented pasta.
7, children's rickets calcium or "D"
With the improvement of per capita living standard and infant health care level in China, most mothers have a certain understanding of rickets in children. Due to the influence of various publicity media, people mistakenly think that calcium supplementation is often the main way to treat and prevent rickets in children. In fact, the essence of rickets in children is the disorder of calcium and phosphorus metabolism caused by vitamin D deficiency, and only vitamin D supplementation can cure it. In other words, calcium deficiency is a sign of rickets in children, but what is really lacking is vitamin D.
/kloc-children under 0/year old are called babies, and their feeding is mainly milk. Rickets common in infancy is also called vitamin D deficiency rickets. The reason is: 1, insufficient vitamin D intake hinders calcium and phosphorus absorption. Vitamin D contained in breast milk or milk can not meet the nutritional needs of infants, especially the improper proportion of calcium and phosphorus in milk hinders its absorption. 2, lack of sunshine, vitamin D deficiency in the body. 3, rapid growth and development, rapid bone growth, relative lack of vitamin D 4. Chronic diseases of liver, gallbladder and gastrointestinal tract affect the absorption of vitamin D.
The effects of vitamin D on calcium and phosphorus metabolism in infants include: 1, which promotes the absorption of calcium and phosphorus by intestinal mucosal cells. 2. Promote the reabsorption of calcium and phosphorus by the kidney, reduce the excretion of calcium and phosphorus in urine, and increase the blood calcium concentration. 3. Promote osteogenic metabolism, which is beneficial to new bone formation. Therefore, when vitamin D is deficient, no matter how much calcium is ingested, it is difficult for the body to absorb and utilize it. The correct understanding is that the root cause of children's rickets is the absolute and relative lack of vitamin D in the body, which leads to calcium and phosphorus absorption disorder, which is manifested as common rickets.
The principles of preventing rickets in children should include: 1, the diet of pregnant women and nursing mothers should be rich in vitamin D and get more sunshine. Children should often do outdoor activities after the full moon. 3. Vitamin D 65438+ 400 units per day will be added 0 months after the child is born. Premature infants should be supplemented with vitamin D at 800 units per day two weeks after birth, and then reduced to 400 units per day three months later. Because the baby is mainly fed with milk, the daily intake of calcium can meet the needs of growth and development, and no special calcium supplement is needed. After two years old, children's growth and development are relatively slow, and outdoor activities increase, so vitamin D supplementation is generally not needed. 6. When it is determined that the baby has rickets, vitamin D should be supplemented under the guidance of a doctor.
In a word, vitamin D supplementation is fundamental to prevent and treat rickets in children.
8. What should I pay attention to when I give my child calcium supplements?
Many parents believe that children should start supplementing calcium from half a month to one month after birth. Actually, this view is unscientific. Because the umbilical cord is cut off after the birth of the fetus, the nutrition channel between the mother and the fetus is also cut off, but the child's growth and development continues, so the daily demand for calcium is indispensable, so the correct way should be to supplement calcium from the third day after birth until the child can eat the same ordinary food as adults.
As we know, baby's nutrition mainly comes from milk, and breast milk is the most ideal baby food. Every 100 ml of breast milk contains 34 mg of calcium and 15 mg of phosphorus, and the ratio of the two is 2.4: 1, which is most suitable for the absorption of calcium by the baby's intestinal wall. Therefore, breast-fed babies are not prone to calcium deficiency or rickets. On the contrary, every 100 ml of milk contains 120 mg of calcium and 93 mg of phosphorus. From the absolute value of calcium and phosphorus, the content of calcium and phosphorus in milk is indeed more than that in breast milk, but the ratio of calcium and phosphorus in milk is 1.2: 1, which is not in line with the physiological needs of infants and is not conducive to the absorption of calcium by intestinal wall. Clinical observation also confirmed that infants fed with milk are prone to calcium deficiency or rickets. Sometimes, although some parents give their children a lot of calcium, the performance of children's calcium deficiency is still obvious. The reason is that parents have not correctly mastered the method of calcium supplementation. So, what problems do you need to pay attention to when supplementing calcium for your child?
1, calcium can't be eaten with plant foods-most plant foods such as vegetables contain oxalate, phosphate and other salts, which can combine with calcium to form polymers and precipitate, thus hindering the absorption of calcium, so tofu and bean products should not be cooked with vegetables.
2, calcium can not be eaten with fatty foods-fatty acids generated after oil decomposition combine with calcium to form milk lumps, which are not easily absorbed by the intestine and eventually excreted with feces.
3, calcium supplementation time should be properly mastered-because the fatty acids in dairy products affect the absorption of calcium, it is best to arrange calcium supplementation between two feedings.
4. Appropriate calcium supplement dosage-children under 2 years old usually need 400-600 mg per day, and children aged 3- 12 years old need 800- 1000 mg per day. According to the normal diet, children's daily intake of calcium from food is only two-thirds of the required amount, so they must take extra calcium every day to make up for one-third of the calcium deficiency. In addition, there are a series of regulatory mechanisms in the human body to control calcium intake. If there is enough calcium in the body, the intestinal tract will absorb less calcium, otherwise it will be more, and the excess calcium will be excreted with urine. Therefore, taking too much calcium orally will not cause poisoning, and parents can rest assured that their children will take it.
It should be emphasized that the absorption of calcium inevitably involves vitamin D. If vitamin D is lacking in the body, the activity of intestinal absorption of calcium will be greatly reduced. If calcium absorption is good, phosphorus absorption will also increase at the same time, forming calcium and phosphorus deposits in the growing bones, so that new bones will continue to grow and grow. The most commonly used vitamin D preparation in clinic is cod liver oil. If you don't supplement cod liver oil while supplementing calcium, and children don't bask in the sun at ordinary times, vitamin D deficiency will occur, leading to rickets. The preventive dose of vitamin D is 400 international units per day, and it cannot be excessive, otherwise it will cause poisoning.
In addition, school-age children also need calcium supplement, but it is not medicine, but supplementary food through three meals a day. There are many sources of calcium in food, such as milk, dairy products, lotus root starch, green leafy vegetables, root plants, soybeans and so on. , especially tofu and soybean milk. If you eat it regularly, you won't lack calcium.
9. Don't take calcium as a tonic.
Calcium is an important component of human bones and teeth, and calcium ions are also necessary for the normal physiological function of all cells. Vitamin D can promote the absorption and utilization of calcium. When vitamin D and calcium are deficient, rickets can occur in infants and osteomalacia and osteoporosis can occur in adults. Infants and young children grow and develop rapidly, but they have little outdoor activities and insufficient light, so they can't synthesize endogenous vitamin D in their bodies. In addition, infants eat fewer kinds of food, which leads to insufficient intake of vitamin D and calcium. Therefore, it is necessary to supplement vitamin D and calcium to infants. In addition to calcium, there are a lot of vitamin D in calcium preparations. Never use calcium as a tonic, or vitamin D poisoning will occur.
If normal children take 20000 ~ 50000 units of vitamin D every day for 1 ~ 3 months, vitamin D poisoning may occur. Poisoning symptoms are mainly caused by blood calcium concentration and calcium deposition. When blood calcium is too high, it will stimulate the secretion of gastrin to increase, and children will have anorexia, nausea, vomiting and intractable constipation. Calcium deposition in the pancreas may lead to acute and chronic pancreatitis. Calcium ion is excreted by the kidney, so when the concentration of calcium ion increases, there will be polydipsia, calcium deposition in the kidney, frequent urination, hematuria, urinary calculi and repeated urinary tract infections, and even renal failure. Repeated respiratory infections can occur when calcium salts are deposited in bronchioles, bronchioles and alveoli. The increase of calcium ion concentration will lead to the increase of osteoblast activity, fibrous osteitis, skeletal deformity and bone pain, and physical development disorder. Vitamin D poisoning can also cause mental symptoms, such as listlessness, lethargy, superficial indifference, hallucinations, mania and even coma.
Once vitamin D poisoning occurs, vitamin D should be stopped immediately, calcium salt intake should be restricted, and blood calcium concentration should be reduced with drugs. Medical experts reminded that the prevention of rickets should focus on strengthening outdoor activities, getting more sunshine, and increasing the amount of foods rich in vitamin D and calcium such as eggs and beans. If you want to supplement calcium, you should also take it under the guidance of a doctor. You can't take calcium as a tonic.
10, rational use of calcium supplements
According to the statistics of relevant departments, Chinese people are seriously short of calcium, and their daily intake is only 50% of the standard. The proportion of calcium deficiency in primary and secondary school students is higher, so people pay more and more attention to calcium supplementation.
There are many kinds of calcium agents used at present, but they can be roughly divided into three categories: ① Traditional chemical calcium: such as various calcium, calcium matrix, calcium gluconate, calcium lactate, calcium carbonate and so on. This pure chemical calcium agent contains low calcium content, and it is often necessary to take 10-40 tablets to meet the daily calcium supplement needs. If you take it for a long time, it is difficult to persist. ② Marine biological calcium: such as raw oyster calcium, active calcium, etc. What is active calcium? Active calcium is the general name of a preparation imported from Japan, and its activity means that its calcium preparation is good and effective. In addition to the word "activity", Japanese pharmaceutical companies also have the words "vitality" or "strength". Activated calcium is formed by ionizing and crushing the shells of marine oysters through a special process. It is water-soluble and easily absorbed by the human body. Under the action of gastric juice, active ionized calcium can be dissociated into calcium ions to the greatest extent, and it is quickly absorbed. Some pharmaceutical factories treat soluble oyster calcium with acid, which contains a variety of trace elements, but it does not rule out the disadvantages that it may contain harmful metals. ③ Other calcium preparations: bone meal, eggshell, etc. Have different calcium contents. Some people think that this kind of calcium is difficult to be absorbed by human body, so it is not an ideal calcium preparation.
Calcium should be supplemented according to different ages and physiological conditions. The daily dietary recommended dietary allowance recommended by China Nutrition Society, in which calcium is: 400mg； from birth to 6 months; 600mg； from 7 months to 2 years old; 3-9 years old 800mg；; 10- 12 years old is 1000 mg; 13-15 years old is1200mg; Adult 16 to 800 mg; Pregnant women1000 mg; Lactating women1500mg; 800 mg for the elderly. Different countries and ethnic groups have different foods, and their daily calcium supplements are also different. If the per capita dietary calcium content of China people is low, about 400 mg/day, it is reasonable to supplement calcium 400 mg/day, that is, to reach 800 mg.
Calcium supplementation should be calculated according to the content of calcium: for example, calcium gluconate contains gluconate and calcium, and calcium lactate contains lactate and calcium. Because the molecular weight of glucose is much larger than that of lactic acid, the content of calcium gluconate in 1g is less than that in1g. The chemical structure of calcium in marine organisms is different, mostly a mixture of calcium oxide and calcium hydroxide, and the calcium content is about 53%. The average human body absorbs 65,438+0,000 mg of calcium and needs 2.05 g of this calcium agent. If you don't pay attention to the content of calcium in calcium supplements, the dosage of calcium will be blind.
The absorption of calcium by human body is influenced by many factors. Under normal diet, the absorption rate of intestinal net calcium is 34%. Protein is digested into amino acids, such as selenium, color, essence, light and sugar, which form soluble calcium salts with calcium to promote the absorption of calcium; The combination of phytic acid and calcium in plant food affects calcium.